Apparatus of this invention relates to fiber feeding, blending and forming of fiber webs of selected density and thickness. The apparatus features controls for varying the rate of feed between multiple sources for varying the blending and feeding to control the density of the fiber web being formed. The arrangement is an improvement over U.S. Pat. No. 5,950,282, issued Sep. 14, 1999, the disclosure of which is incorporated herein.
Fiber blending and fiber web forming systems are well-known in the industry. Various contemporary arrangements are shown in U.S. Pat. Nos. 4,694,538; 4,657,444; and 4,520,530. None of these patents teach the system of controlled blending and controlled fiber web density as herein disclosed.
The invention has for an object a blending system which receives fibers from a plurality of sources at controlled rates.
Another object of the invention is an improved multi-source fiber feeding and blending system.
Another object of the invention is a controlled feed for delivery of fibers of a selected blend to a beater.
Another object of the invention is a fiber web forming chute which provides a positive drive for movement of the fibers into a compacted fiber web.
Another object of the invention is a fiber web forming chute which may be adjusted to accommodate different thicknesses or density variations.
Another object of the invention is a control system responsive to sense fiber volume in the web forming chute and being responsive to change the fiber volume to desired levels.
Another object of the invention is a control system operative to change the size of the web forming chute in accordance with a selected fiber volume and web fiber density.
Another object of the invention is a variable speed, positive feed for the fiber web forming chute.
Another object of the invention is a control system, which in response to unwanted fiber web density sensings, acts to bring about change of density in subsequent fiber webs being formed.
The instant invention is directed to an apparatus for forming a non-woven fiber web or non-woven fabric of fibrous material. The apparatus includes a feed having a plurality of feed chutes for feeding fibers from a plurality of sources. The discharge ends of the feed chutes connect with a housing which includes a mixing chamber, a beater chamber and a fiber web forming chute.
The mixing chamber includes a feed roll adjacent each discharge end of each feed chutes which withdraw the fibers from the feed chutes and deliver them into the mixing chamber. Preferably, the feed rolls are of different diameters. A combing roll within the mixing chamber acts to move the fibers from the mixing chamber into a beater roll chamber which further blends and opens the fibers during delivery to the web forming chute.
The system may provide independent drives for each of the feed rolls, the comber roll and the beater roll, which drives are capable of being controlled to drive each roll at selected peripheral speeds.
The feed rolls, the combing rolls and the beater rolls each have protruding teeth forming their outer surfaces. The teeth forming the surface of at least one of the rolls form a helical bite.
The system includes a control which is capable of causing each drive to drive its particular roll at selected RPM""s.
The fiber web forming apparatus of the invention includes a fiber web forming chute which receives the mixed fibers from the beater roll and forms them into a fiber web. The web forming chute includes an upper and a lower wall, a delivery end and a receiving end. A packing belt extends from the vicinity of the receiving end to the vicinity of the delivery end and forms at least a portion of one of the upper and lower walls.
An independent drive is provided for driving the packing belt in the direction of the delivery end.
A vibrating plate is located in and forms at least a portion of the other of the upper and lower walls, preferable the upper wall. An independent drive is provided for driving the vibrating plate.
The fiber web forming chute includes a mounting structure which acts to adjustably position the packing belt relative to the vibrating plate.
A control is provided to selectively position the packing belt in response to the selected volume of fibers fed into the web forming chute and the selected density of the fiber web being formed.
A compression roll is located adjacent the delivery end of the web forming chute. The compression roll acts to further compress the fibers forming the fiber against a delivery surface during its exodus from the web forming chute. The compression roll mounting structure permits movement of the compression roll relative to the delivery surface in dependence upon the density of the fiber web emerging from the delivery end. A control which varies the operational speed of the drive of at least one of the packing belt and the vibrating plate responsive to the position of the compression roll is provided. The movement of the compression roll as controlled by the density of the fiber web operates the control to vary the speed of at least the packing belt.
A conveyor receives the fiber web emerging from the fiber web forming chute and the compression roll. The conveyor includes a scale for weighing the fiber web during delivery to further processing. The scale is effective to signal a control which, in response to the signal, controls the operational speed of at least one of said packing belt and said vibrating plate.
The web forming chute includes a sensor which detects an absence of fibers in the web forming chute or an excess of fibers in the web forming chute. The sensor is connected with a control which acts to control at least one of the feed roll, the comber roll and the beater roll drives and is operative to selectively adjust the peripheral speed of each of these rolls in dependence upon these sensings.